Clogged Cooling Ports

Purchased a '93 with a blown head gasket. From what the previous owner told me, it was not the original engine and was from an other '93 SC. Anyways, upon tearing down the top end and taking off the heads, I find the drivers side head gasket to be very clogged where the cooling ports are.

From what it looks like, a bunch of rust. I would say that nearly 5 ports were clogged. For some reason, it wasn't the driver side HG that blew, it was the passenger's side. The upper neck where the upper radiator hose connects (on the engine) doesn't look so well either. A lot of rust on the end of it, to the point that it looks brittle.

From your guy's experience, should I be supper worried about this whole project? The current radiator looks great, virtually no rust inside (that I could see). Is there a realistic way to go about cleaning out the cooling ports on the engine (compressed air)? I'm on a shoe string budget and using a friend's garage, if that matters. Thanks in advance.

doesn't sound good. I would expect your freeze plugs are not in good shape. Someone didn't stay on top of their coolant changes.

Most of the block is hollow around the cylinders. I'd be tempted to pop some freeze plugs, and flush the block with water. Flush the heads as well.

expect the heater core isn't gonna be in good shape either. Those steel coolant lines that round around the outside of the block could be ready to pop a hole as well.

The cooling passages in the head gaskets are deliberately closed at the front of the engine and open up larger going to the back with the last couple of coolant holes are full open.

This is deliberate as the coolant has to flow through the block from front to back, then up into the heads, and flows back to front there.

You may be seeing some of the gasket residue left from peeling them off.

Frit

I have some pics of the HGs that I'll try to get up later on today. For the opening size of the ports on the heads, to allow better flowing/cooling to the rear of the engine: Is the port sizing due to the HG or the design of the block/head? I ask because I remember a thread where someone ported their HGs to match the heads and block... just wondering if that's a good thing to do in regards to sufficient cooling to the rear of the engine (Too much up front, not enough in the back).

SlowTK said:

I ask because I remember a thread where someone ported their HGs to match the heads and block... just wondering if that's a good thing to do in regards to sufficient cooling to the rear of the engine (Too much up front, not enough in the back).

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Nope.. leave them the way they are.

The coolant is pushed into the block on both sides by the water pump. It travels towards the back of the block where it then runs up into the heads and forwards... a small amount diverts up along the way. If you mess with the size of the ports.. you'll unbalance the heat transfer.. Just flush the block+heads as best as you can and run 50/50 water antifreeze.

this picture shows a piece of RTV pulled out of a small hole in the front of the head gasket on my 90 when I had to change them. That small hole was blocked by the RTV.

Porting the head gasket for the cooling passages is foolish. The water pump pushes coolant into the front of the block, this then migrates via pressure and heat rise through the block and to the heads. Then through the heads and out through the intake manifold by the thermostat.

If the front cooling passages had full flow, no circulation at the rear of the block would occur as the fluid would short circuit past the rear of the heads and just go right out the thermostat at the front. By limiting the front coolant passages, the coolant makes a path that runs from the back of the head towards the front of the head, and then out the thermostat. This allows coolant to flow through the entire block and heads rather than just the front half.

To best spin way off topic, you may consider soaking some of the parts in white vinegar. Its cheap at the bluk stores (cost co...) and can cover great areas. The acidity helps break down build up. If the engine is all down, the radiator is probibly open for filling and allowing to soak for a few days.

As of right now, only the top end of the motor is apart. I would have liked to have done a full rebuild but I just don't have the budget or the time to do so (mainly, budget). So, not a whole lot of parts would be able to get soaked in the vinegar, though, I do like the idea of it.

P.S. Still working on getting the pics of the clogged/blocked ports up

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Now that I have looked at the clogged ports a bit closer, it appears that there is still a hole to allow cloolant to flow through. I guess I was possibly just getting a little too worked up over the amount of junk around that area. Even still, I have some rust issues that need to be dealt with.

You need to take a look at my HG job pictures from my black SC. I flushed the block out with a garden hose... pistons, lifters, camshaft, and all Then took it out for 200+ miles of high speed track duty.

Take a hard look at the frost plugs. Once you get it all together but before you put the accessory brackets back on, pull a couple out and push the car outside. the flood the block with water to flush out all the rust. then when you button it back up, add a gallon of just anti-freeze, and then top off with 50/50 mix. run the motor for a while to mix everything up real good.